Feeling sociable or reckless? You might have toxoplasmosis, an infection caused by the microscopic parasite Toxoplasma gondii, which the CDC estimates has infected about 22.5 percent of Americans older than 12 years old. Researchers tested participants for T. gondii infection and had them complete a personality questionnaire. They found that both men and women infected with T. gondii were more extroverted and less conscientious than the infection-free participants.

actually, the real danger of toxoplasmosis is that if you are pregnant when you get infected, it can affect your baby.